Measuring arrangements for determining magnetic-field gradients serve in particular a potential-free measurement of current intensity of an electric current which is the source of such a magnetic field. Since the entire surroundings of a magnetic field to be determined in this manner has always encountered stray electro-magnetic interference, it is obvious to differentiate, with the help of magnetic-field gradients, between the one to be measured and electro-magnetic interference.
Such arrangements are already known from DD Patent Nos. 155 220 and 275 745. Magnetoresistive sensor elements are thereby utilized since their sensitivity is sufficiently great in order to sense currents over a large measuring range. The linearity range of such sensor elements is, however, limited. Their actually high sensitivity depends much on the temperature and on an auxiliary magnetic field to be applied to the sensor elements. Moreover, the sensitivity of the individual sensor elements differs greatly.
The purpose of the invention is therefore to avoid these disadvantages and to provide a sensor chip of the type identified in greater detail above such that the output signal is proportional to an electric current to be measured, that its sensitivity depends neither on the temperature nor the auxiliary magnetic field and always has approximately the same sensitivity.